Field of Invention
The present invention belongs to the field of material technology, and particularly relates to a sulfur doping method for graphene.
Description of Related Arts
Graphene is a plane monatomic thin film material formed by two-dimensional regular hexagonal honeycombed lattice configured by carbon atoms. Because the graphene has a series of properties such as prominent heat-conducting property and mechanical property, high electronic mobility, semi-integer quantum halls effect, etc., it has attracted widely attention in the scientific community and raised research upsurge since its first discovery in 2004.
Graphene is bonded by sp2 hybrid carbon atoms, and has monolayer plane graphite of two-dimensional structure of hexagonal lattice honeycomb, and has extremely high crystal quality and electrical property. As a strict two-dimensional crystal material, the graphene has unique physics property, with a carrier concentration up to 1013 cm-2 and a mobility ratio over 20000 cm2V-1 s-1, thereby providing material basis for the preparation of high performance devices, e.g., transistor, sensor and the like.
The connection among carbon atoms inside the graphene is quite flexible, and when external force is applied to the graphene, the carbon atomic plane will be bended and deformed, such that it is not necessary for rearranging the carbon atoms to adapt to the external force, thereby maintaining its stable structure. The stable lattice structure enables the graphene to have excellent thermal conductivity. Additionally, when electron of the graphene moves in its orbit, a scatter will not occur due to lattice imperfection or introduction of foreign atoms. Since inter-atomic forces are relatively strong, even though surrounding carbon atoms jostle at room temperature, the suffered interference of the electrons inside the graphene is also relatively small. The emergence of graphene has aroused large wave in the scientific community, and it has been found that, graphene features extraordinary conductivity property, strength dozens of times of steel as well as excellent transmittance, and its emergence is expected to cause a revolution in the field of modern electronic technology. In graphene, electron enables to migrate very effectively, while the performance of traditional semiconductors and conductors, e.g., silicon and copper, is far less than that of the graphene. Because of the collision of electron and atom, the traditional semiconductors and conductors release some energy in a manner of heat, and the current general chips of computers may waste 70%-80% of electric energy in such manner, whereas the graphene is totally different that its electron energy will not dissipate, with the result of extraordinary excellent property.
As a zero-band gap semiconductor, graphene can be applied to microelectronic device with an importance premise that its band gap as well as carrier concentration are adjustable, while chemical doping is an effective method for realizing the adjustment. Theoretical calculation indicates that, sulfur doped graphene has significant application prospect in a detection aspect of oxynitride gas. As present, doping methods of graphene mostly focus on N-doping, including preparing N-doped graphene by taking methane and ammonia gas as carbon and nitrogen source at high temperature by using chemical vapor deposition method; and achieving reduction of oxidized graphene and N-doping of graphene by performing high temperature annealing of melamine and oxidized graphene, etc. There are few reports on sulfur doping for graphene, only Gao Hui et al of Lanzhou University have reported that S-doped graphene is prepared on a metal substrate by dissolving elemental sulfur into hexane as a liquid sulfur source by chemical vapor deposition.